/*
 * Copyright (c) 1999, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.misc;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Vector;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

/**
 * This class is used to maintain mappings from packages, classes and resources
 * to their enclosing JAR files. Mappings are kept at the package level except
 * for class or resource files that are located at the root directory.
 * URLClassLoader uses the mapping information to determine where to fetch an
 * extension class or resource from.
 * 
 * @author Zhenghua Li
 * @since 1.3
 */
@SuppressWarnings("rawtypes")
public class JarIndex {

	/**
	 * The hash map that maintains mappings from package/classe/resource to jar
	 * file list(s)
	 */
	private HashMap indexMap;

	/**
	 * The hash map that maintains mappings from jar file to
	 * package/class/resource lists
	 */
	private HashMap jarMap;

	/*
	 * An ordered list of jar file names.
	 */
	private String[] jarFiles;

	/**
	 * The index file name.
	 */
	public static final String INDEX_NAME = "META-INF/INDEX.LIST";

	/**
	 * Constructs a new, empty jar index.
	 */

	public JarIndex() {
		indexMap = new HashMap();
		jarMap = new HashMap();
	}

	/**
	 * Constructs a new index from the specified input stream.
	 * 
	 * @param is
	 *            the input stream containing the index data
	 */
	public JarIndex(InputStream is) throws IOException {
		this();
		read(is);
	}

	/**
	 * Constructs a new index for the specified list of jar files.
	 * 
	 * @param files
	 *            the list of jar files to construct the index from.
	 */
	public JarIndex(String[] files) throws IOException {
		this();
		this.jarFiles = files;
		parseJars(files);
	}

	/**
	 * Returns the jar index, or <code>null</code> if none.
	 * 
	 * @param jar
	 *            the JAR file to get the index from.
	 * @exception IOException
	 *                if an I/O error has occurred.
	 */
	public static JarIndex getJarIndex(JarFile jar, MetaIndex metaIndex)
			throws IOException {
		JarIndex index = null;
		/*
		 * If metaIndex is not null, check the meta index to see if
		 * META-INF/INDEX.LIST is contained in jar file or not.
		 */
		if (metaIndex != null && !metaIndex.mayContain(INDEX_NAME)) {
			return null;
		}
		JarEntry e = jar.getJarEntry(INDEX_NAME);
		// if found, then load the index
		if (e != null) {
			index = new JarIndex(jar.getInputStream(e));
		}
		return index;
	}

	/**
	 * Returns the jar files that are defined in this index.
	 */
	public String[] getJarFiles() {
		return jarFiles;
	}

	/*
	 * Add the key, value pair to the hashmap, the value will be put in a linked
	 * list which is created if necessary.
	 */
	@SuppressWarnings("unchecked")
	private void addToList(String key, String value, HashMap t) {
		LinkedList list = (LinkedList) t.get(key);
		if (list == null) {
			list = new LinkedList();
			list.add(value);
			t.put(key, list);
		} else if (!list.contains(value)) {
			list.add(value);
		}
	}

	/**
	 * Returns the list of jar files that are mapped to the file.
	 * 
	 * @param fileName
	 *            the key of the mapping
	 */
	public LinkedList get(String fileName) {
		LinkedList jarFiles = null;
		if ((jarFiles = (LinkedList) indexMap.get(fileName)) == null) {
			/* try the package name again */
			int pos;
			if ((pos = fileName.lastIndexOf("/")) != -1) {
				jarFiles = (LinkedList) indexMap
						.get(fileName.substring(0, pos));
			}
		}
		return jarFiles;
	}

	/**
	 * Add the mapping from the specified file to the specified jar file. If
	 * there were no mapping for the package of the specified file before, a new
	 * linked list will be created, the jar file is added to the list and a new
	 * mapping from the package to the jar file list is added to the hashmap.
	 * Otherwise, the jar file will be added to the end of the existing list.
	 * 
	 * @param fileName
	 *            the file name
	 * @param jarName
	 *            the jar file that the file is mapped to
	 * 
	 */
	public void add(String fileName, String jarName) {
		String packageName;
		int pos;
		if ((pos = fileName.lastIndexOf("/")) != -1) {
			packageName = fileName.substring(0, pos);
		} else {
			packageName = fileName;
		}

		// add the mapping to indexMap
		addToList(packageName, jarName, indexMap);

		// add the mapping to jarMap
		addToList(jarName, packageName, jarMap);
	}

	/**
	 * Go through all the jar files and construct the index table.
	 */
	private void parseJars(String[] files) throws IOException {
		if (files == null) {
			return;
		}

		String currentJar = null;

		for (int i = 0; i < files.length; i++) {
			currentJar = files[i];
			ZipFile zrf = new ZipFile(currentJar.replace('/',
					File.separatorChar));

			Enumeration entries = zrf.entries();
			while (entries.hasMoreElements()) {
				String fileName = ((ZipEntry) (entries.nextElement()))
						.getName();
				// Index the META-INF directory, but not the index or manifest.
				if (!fileName.startsWith("META-INF/")
						|| !(fileName.equals("META-INF/")
								|| fileName.equals(INDEX_NAME) || fileName
									.equals(JarFile.MANIFEST_NAME))) {
					add(fileName, currentJar);
				}
			}
			zrf.close();
		}
	}

	/**
	 * Writes the index to the specified OutputStream
	 * 
	 * @param out
	 *            the output stream
	 * @exception IOException
	 *                if an I/O error has occurred
	 */
	public void write(OutputStream out) throws IOException {
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out,
				"UTF8"));
		bw.write("JarIndex-Version: 1.0\n\n");

		if (jarFiles != null) {
			for (int i = 0; i < jarFiles.length; i++) {
				/* print out the jar file name */
				String jar = jarFiles[i];
				bw.write(jar + "\n");
				LinkedList jarlist = (LinkedList) jarMap.get(jar);
				if (jarlist != null) {
					Iterator listitr = jarlist.iterator();
					while (listitr.hasNext()) {
						bw.write((String) (listitr.next()) + "\n");
					}
				}
				bw.write("\n");
			}
			bw.flush();
		}
	}

	/**
	 * Reads the index from the specified InputStream.
	 * 
	 * @param is
	 *            the input stream
	 * @exception IOException
	 *                if an I/O error has occurred
	 */
	@SuppressWarnings("unchecked")
	public void read(InputStream is) throws IOException {
		BufferedReader br = new BufferedReader(
				new InputStreamReader(is, "UTF8"));
		String line = null;
		String currentJar = null;

		/* an ordered list of jar file names */
		Vector jars = new Vector();

		/* read until we see a .jar line */
		while ((line = br.readLine()) != null && !line.endsWith(".jar"))
			;

		for (; line != null; line = br.readLine()) {
			if (line.length() == 0)
				continue;

			if (line.endsWith(".jar")) {
				currentJar = line;
				jars.add(currentJar);
			} else {
				String name = line;
				addToList(name, currentJar, indexMap);
				addToList(currentJar, name, jarMap);
			}
		}

		jarFiles = (String[]) jars.toArray(new String[jars.size()]);
	}

	/**
	 * Merges the current index into another index, taking into account the
	 * relative path of the current index.
	 * 
	 * @param toIndex
	 *            The destination index which the current index will merge into.
	 * @param path
	 *            The relative path of the this index to the destination index.
	 * 
	 */
	public void merge(JarIndex toIndex, String path) {
		Iterator itr = indexMap.entrySet().iterator();
		while (itr.hasNext()) {
			Map.Entry e = (Map.Entry) itr.next();
			String packageName = (String) e.getKey();
			LinkedList from_list = (LinkedList) e.getValue();
			Iterator listItr = from_list.iterator();
			while (listItr.hasNext()) {
				String jarName = (String) listItr.next();
				if (path != null) {
					jarName = path.concat(jarName);
				}
				toIndex.add(packageName, jarName);
			}
		}
	}
}
